Gas and liquids separator



Sept. 16, 1952 ML. EDWARDS 2,610,788

GAS AND LIQUIDS SEPARATOR Filed Aug. 11, 194B 3 Sheets-Sheet 1 MZes Lowell Edzaands p 1952 M. L. EDWARDS 2,610,788

GAS AND LIQUIDS SEPARATOR 3 Sheets-Sheet 5 Filed Aug. 11, 1948 [HI/P177271" M265 Lowell .E'dwards' z a! 2 24, 4Z5 7 [7272 5 application entitled:

Patented Sept. 16, 1952 UNITED STATES PATENT OFF-ICE GAS AND Llir s sEPARATbR I Miles Lowell Edwards, Longview, Wash. I

Original application May 23, 1945, Serial No. 595,467. Divided and this application Angus 11, 1948, Serial No. 43,703

This invention relates to the separation of foam into its constituent gaseous and liquid components, and particularly relates to the control of foaming lubricant in engines and the like.

This application is a division of my eopending Gas and Liquids Separator, U. S. Serial No. 595,467, filed May 23, 1945, patented November 13, 1951, No. 2,575,315.

The invention will be hereinafter specifically described in connection with aircraft engines, but it should be understood that the principles of this invention are generally applicable to the reduction or breaking of foam for reclaiming at least the liquid component of the foam.

Considerable difliculty has been experienced in connection with the oil systems of high altitude aircraft engines due to foaming of the oil or other lubricant, caused by expansion of entrained air and vaporization of volatiles in the oil. Gas and vapor bubbles are released from the lubricant due to reduced ambient air pressures when operating at high altitudes, as well as elevated temperatures created by the engine. These bubbles are encased in thin films of the liquid lubricant and create foam which tends to spew out of the vents provided in the oil system. In addition, this foam cannot be efficiently pumped and, in some instances, causes the pumps of the oil system to become gas-bound thereby resulting in failure of the lubrication system for the engine.

In accordance with this invention, the lubricant systems for engines are equippedwith foam-reducing devices which separate foam into its constituent gaseous and liquid components.

These devices have separate gaseous and liquid outlets with the gaseous outlet forming the vent for the lubricant system, and with the liquid outlet returning the reclaimed fully liquid lubricant to the system. The devices of this invention comprise a rotor having an axial inlet, a peripheral liquids outlet, and an axial gaseous material outlet. The rotor contains blades for centrifugally whirling the foam to create a centrifugal force tending to crush the foam bubbles and centrifugally throw the liquid component outwardly from the gaseous component. The liquid component is centrifugally discharged through the peripheral outlet of the rotor into a pumping chamber or volute provided by a casing surrounding the rotor. The. lighter gaseous material is discharged through the axial outlet of the rotor into an annular chamber having a peripheral outlet separate from the outlet for the liquids pumping chamber or 'volute. v p

,9 Claims. (01. 233-21 The rotor is preferably equipped with a baflle adjacent the axial inletthereof for directing the foam toward the periphery of the rotor'to in-E sure centrifugal whirling and to prevent axial flow of foam through the rotor. Radial vanes'are provided on the rotor adjacent the peripheral discharge outlet to prevent leakage of the liquid in the pumping chamber or volute back into the rotor. v l

The devices of this invention are preferably arranged with a drive shaft that can be coupled at either end to a driving member, and can trans mit power from this driving member to another driven member. The casing for the device is preferably formed with mounting flanges on both ends thereof so that the device can be incorporated between driving and driven parts with the shaft of the device transmitting power from the driving to the driven device. Y

. It is, then, an object of this invention to provide a foam-reducer venting devicesfo'r engine crankcases or the like. I I

Astill further object of this invention is to provide a gas-liquid separator of the centrifugal type wherein the liquid component is centrifugally pumped out of the device afterit has been separated fromthe gaseous component of the lubricant. I

A specific object of the invention is to provide a gas-liquid separator with a rotating cham-. her having an'axial inlet, a'peripheral liquids outlet, and an axial gasoutlet. e

A still further object of this invention is to provide a foam reducer of the centrifugaltypeadapted to be mounted on an engine between driving and driven parts of the engine. a

A further'speciflc'object of the invention is to provide a rotor for a gas-liquid separator which diverges from an axial inlet at one end thereof Figure 2 is a somewhat diagrammatic front and elevational view of an in-line eng ine havingan oil ystem equipped with a] gasgliquid separator of this invention in the breather passage thereof.

Figure 3 is a fragmentary side elevational view of a portion of the assembly shown in Figure 2.

Figure 4 is an axial cross-sectional view of the gas-liquid separator of this invention.

Figure 5 is a fragmentary elevational view of a portion of the rotor of the device shown in Figure 4 and taken along the line V-V.'of Figure 4.

Figure 6 is a transverse cross-sectional view taken along the line VIVI of Figure 4.

Figure '7 is an end elevational view or plan view of the device of this invention taken along the line VII-VII of Figure 4.

Figure 8 is a transverse OTOSSrSGOtiOIXSJ view taken along the line VIII-47111 of Figure 4.

As shown on the drawings:

As shown in Figure 1, the reference numeral I0 designates generally a radial aircraft engine driving a crankshaft Ii. The engine I0 has a lubricating system receiving oil from a storage tank l2. An oil pump i3 pumpsoil from thetank 12 through a conduit or tube [4 into the crankcase [0119f the engine it. The'pump-I3'isdriven from the crankshaft H as by means-of gears i5.

An oil-scavenger pump i3 is mounted on the casing I011 to circulate oil from the crankcase back to the tankl2 through a pipe or tube 11. A gear 13 on the crankshaft il engages a gear I! on the shaft of the scavenger pump it to drive the pump.

In accordance with this invention, an air-oil separator 20 is mountedon the upper portion of the casing Illa and has an axial inlet projecting into the casing to vent air in the casing to the atmosphere. The separator 23 has a'rotor driven by a gear 2| engaging the same gear'18 that drives the scavenger pump it.

A tube 22 connects the oil outlet port of the separator 23 with a valve 23 havingoutlet ports respectively receiving tubes 24 -and25. The tube 24 discharges the oil back into the casing [0a. The tube'25 discharges the oil into the tank i2. The valve 23can be set so that oil is either drained back into the engine casing, or circulated back to the storage tank I2.

The air outlet for the separator 20 receives a tube 26 which opens into the slipstream of the aircraft (not shown) on which the engine is mounted. This tube 26 opens. downstream to aid in circulating air through the separator, thereby providing a breather for-the engine casing.

The air-oil separator illustrated in the oil system for the engine I0 is effective for venting the engine casing No to theambient air and for breaking up foam tending to flow through the breather or vent passage. The oil component of the foam is pumped by the device 20 either back to the engine casing or: to the oil storage tank.

The device 20 is also readily'mounted. On inline engines as shown in Figures 2 and 3, and, as illustrated, can be conveniently mounted between thegeneratorand a drive shaft extending from a pump or other driven appurtenance of the engine. As shown in Figure 3, an in-line engine 21 has the crank shaft 28 thereof rotatably mounted in a crankcase 21a of the engine. A side wall of this crankcase 21a has a vent port or opening registering with an inlet port23a of a hollow casing 29. This casing 29 has an outlet port 29b receiving theinlet end of the separator 20 therein. A pump or other engine-driven shaft 30 extends through the casing 29 and is coupled with the drive shaft of the separator 20. The

separator 20 is bolted to the engine generator 4 3| and the shaft for the separator 20 transmits power from the shaft 30 to the generator shaft. The oil outlet for the separator 20 is connected to a tube 32 to return oil to the oil system for the engine 21. The air outlet for the separator 23 is connected through a breather pipe or tube 33 which, as shown, opens downstream under the engine 21.

The crankcase 21a for the engine is thus vented through the casing 29, separator 20, and breather pipe 33 but the separator removes liquid from the gaseous material flowing therethrough and returns this liquid back to the oil system for the engine;

From the above descriptions it is clear, therefore. thatthe'separator 20 of this invention is readily adapted for mounting either on a radial engineer an in-line engine, and can be interposed between driving and driven members on the engine to transmit driving torque.

As shown in Figure 4, the separator 20 comprises a main casing 34 having circular mounting flanges'34a and 341) at the ends thereof and receiving a cap 35 in the flanged end 34a to cooperate therewith in defining a frusto-conical chamber 36. An annular pumping chamber 31 is provided in the casing 34 .at the large end of the frusto-conical chamber 33. An axial inlet opening 38 is provided'in the central portion of the cap 35 at the small end. of the frusto-conicai chamber 33. As best. shown in Figures 7 and 8, the casing 34 has a peripheral boss 34c providing a discharge. outlet 39 for the pumping chamber 31. A leg 3411 (Figs. 481141 8) provides'an oil drain passageway 43 for the chamber 31. A partition wall 340. is provided. in thecasing 34 forming an end wall for the chamber 36 and 31. An air chamber 41 isprovided inthecasing on the side of the partition 5718-11446 opposite the chamber 31. This chamber. has a Peripheral outlet 42 provided in a, boss! on the cesium An end wall 340 on the casing provides a closure-for the chamber and a seat for a bearing 43. This bearing is retained in the seat by meansof. a. ring 4 secured to the well 3441 by means of screws"- The bearing 43 rotatably supports a shaft 43 which extends axially through the casing 34 and aperture, 38 of the cover 35. The end of the shaft 46 extendingthrough the aperture 38 is externally splined at 46a while the opposite end of the shaft is internally splined as at 46b. The shaft is thus adapted tobe coupled to driving and driven means. I

As shown in Figure 4, the innerrace ring for the bearing 43 is clamped between a shoulder 430 on the shaft and a collar 46d seated on the shaft. The bearing 43 thus rotatably supports the shaft 46 in the central portion-of the casing 34 and the shaft projects through large openings in the partitionwall 34c and endwall 34cv of the 0851118.

A frusto-conical hollow rotor 41' is mounted in the casing 34. and cover 35 on the'shaft 43. This rotor has a hollow hub 48 .snugly engasins the shaft and abutting the collar 4311 on the shaft. This hub .48 has a collar 49 secured thereon intermediate the ends thereof with an outturned flangev 43a that i radially slotted at 43b at spaced intervals therearound as shown in Figure 8.

The hub 48is-drivingiy connected to the shaft 46 by serrations 46c on the shaft meshed with internal serrations in the hub. The rotor casing 41 has an end wall fla at the small end thereof with-a central aperture 41b therethrough aligned with the opening 33. A face plate or ring 30 is welded to theends of radial blades 53 which extend beyond the large end of the rotor casing 41 as best shown in Figure 5. These extended ends of the vanes 53 provide gaps or discharge ports 52 between the end of the casing 41 and the plate 50 aligned with the pumping chamber 31. The plate has a depending collar or neck portion 50a extending into the large end of the rotor 41.

The radial rotor blades 53 are mounted in the rotor 41 and have outer end portions 53a extending from the rotor wall 41a to the plate 50. These outer end portions 53a have inner edges 53b spaced somewhat radially outward from the opening 41?) in the end wall 41a of the rotor together with converging edge portions 530 merging into short blade portions 53d snugly fitted on the rotor hub 48 and seated in the slots 4% of the collar flange 49a. The blades 53 then have diverging edges 53e extending outwardly to the straight edge portions 53}. The edges 53f terminate in flat shoulders 53g abutted against the collar 50a of the end plate 50.

Radial vanes 54 are provided on the plate 50 and have close-running clearance relationship with the partition wall 34c of the casing 34. These radial vanes 54 have axial vane portions 54a on the neck or collar 50a of the plate 50 aligned flush with the blade edges 53]. A collar 55 is threaded into the partition wall 34c and projects to form a tube inside of the vane portions 54a in close-running clearance relationship therewith. The collar terminates in spaced relation from the shoulders 53g of the blades 53.

A collar 56 is mounted on the hub 48 in spaced opposed relation to the collar 49' and abuts the blade portions 5301. The opposite ends of these blade portions 53d are bottomed on the collar 49. The collar 56 has a skirt 56a diverging therefrom toward the rotor inlet 4122. This skirt 56a is radially slotted as at 56b to receive the blade portions 53a and cooperate with the slotted flange 4% of the collar 49 to, space and rigidify the blades 53.

A nut 51 is threaded on the shaft 48 and a lock washer 58 is pressed by the nut against the collar 56. This collar 56 has a slot therein receiving a tang 58a on the lock washer to prevent the nut from loosening. As indicated above the serrations 4te on the shaft drive the hub 48.

In operation, the device 20 is mounted on a motor casing so that the inlet 38 thereof is adapted to receive 011 foam. This foam enters the inlet 41b of the rotor 41. The shaft 46 is splined to some driven part of the motor to be rotated at high speed. Foam entering the rotor inlet 41b is deflected by the baffle skirt 56a into the path of the blades 53a whereupon centrifugal force will throw the heavier liquid component of the foam against the conical side wall of the rotor. The liquid will flow by centrifugal action to the large end of the conical rotor 41 where it is centrifugally discharged through the openings 52 into the pumping chamber 31. The impact of the centrifugally discharged oil at high velocity against the stationary walls of the pumping chamber 31 creates a vortex action which develops a pressure head for discharging the oil out of the peripheral outlet 39 and back to the oil system of the engine as described in connection with Figures 1 to 3.

The gaseous component of the foam, being lighter than the liquid, will gather close to the axial center of the rotor chamber to flow through the outlet tube 55 into the annular air chamber 4| from which it is discharged out of the peripheralioutlet 42 into the breather discharge tube 26 or 33 as described in Figures 1 to 3. The vanes 54 and 54a have close-running clearance with the partition wall 34c and discharge tube 55 which prevents leakage of air from the central'portion of the rotor into the liquid pumping chamber 31 and likewise prevents back-flow of oil from this pumping chamber into the rotor.

The oil drain 40 is arranged for gravity drainage of oil out of the pumping chamber 31 when the engine is at rest to prevent loss of oil through the breather passageway. This drain passage 40 communicates with the crankcase of the engine for gravity drainage of oil back to the crankcase.

From the above descriptions it should be understood that this invention provides a foam breaker or foam reducer device for incorporation in the breather passage of a lubricant system for internal combustion engines and the like. The device of this invention is preferably driven by the internal combustion engine and includes a rotor which centrifugally separates foam into its constituent gaseous and liquid parts while actually pumping the liquid part back to the system. The gaseous component of the foam escapes to the ambient air surrounding the engine, and flow of the gaseous component can be induced by a slight suction created by the slipstream of the vehicle propelled by the engine. The devices of this invention minimize difficulties experienced with foam or froth formation in oil systems. preventing the loss of oil from such systems while still permitting the system to be vented, and insure a supply of fully liquid oil to the oil pumps of the system.

It will, of course, be understod that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. A liquid-gas separating device comprising a casing having an axial inlet at one end thereof and two separate peripheral outlets at the other end thereof, a shaft rotatably carried insaid casing, a frusto-conical rotor mounted on said shaft having an axial inlet at the small end thereof registering with the axial inlet of the casing and a peripheral outlet at the large end thereof communicating with one ofthe peripheral outletsof the casing, blades in said rotor for whirling material received from the inlet to centrifugally separate the material into gaseous and liquid components, vanes on said rotor in close running clearance relation to the casing for pro venting leakage of gas from the axial outlet to the peripheral outlet of the rotor and for preventing back flow of liquids from the peripheral outlet of the rotor to the axial outlet, annular partition means between said blades and said vanes, and an axial outlet at the large end of the rotor communicating with the other of said peripheral outlets of the casing.

2. A foam-reducing device comprising a casing having an axial inlet at one end thereof and a pair of annular chambers at the other end thereof, a shaft rotatably mounted in said casing, a rotor mounted on said shaft having an inlet registering with the axial inlet of the casing and a side wall diverging from said inlet to a peripheral outlet aligned with one of said annular chamberspofthe casing, atube mounted in said casing Joining the other of said annular casing chambers with the central portion of said rotor at the divergent end of the rotor, blades in said rotor arranged for centrifugally separating gas and liquid entering the rotor from said casing inlet to centrifugally discharge the heavier liquid out of the peripheral outlet of the rotor into the aligned casing chamber while allowing axial flow of the lighter gas along the axial portion of the rotor through said tube into the other of said annular chambers of the casing, means in said aligned casing chamber rotatable with said shaft for preventing back-flow of the heavier liquid toward said tube and for preventing leakage of gas from said tube toward said peripheral outlet, and a plate between said blades and said means.

3. A device for reducing foam which comprises a casing defining an operating chamber with an axial inlet at one end and a peripheral pumping chamber at the other end, a rotor rotatably mounted in said operating chamber having a side wall diverging from said axial inlet of the casing to said pumping chamber, said rotor having an axial inlet registering with the inlet of the casing and a peripheral outlet registering with said pumping chamber, said rotor having an axial outlet at the divergent end thereof, blades in said rotor for centrifugally whirling material received from said inlet to separate the material into gaseous and liquid components for discharge of the heavier liquid through said peripheral outlet while allowing discharge of the lighter gaseous component through said axial outlet, vanes carried by said rotor in said pumping chamber for preventing back flow from said pumping chamber toward said axial outlet and for preventing leakage of gas from said axial outlet to said pumping chamber, and partition means between said blades and said vanes.

4. A centrifugal liquid-gas separator comprising a casing having an axial inlet at one end, separated outlets at the other end, and a rotor chamber between the axial inlet and outlets, a rotor in said chamber having a side wall diverging from an axial inlet aligned with the casing inlet to a peripheral outlet discharging into one of the casing outlets, means defining a passageway connecting the central portion of the divergent end of the rotor with the other casing outlet, internal radial vanes in said rotor for whirling fluid received from the inlet to centrifugally separate the heavier and lighter constituents thereof and discharge the lighter constituents through said passageway and the heavier constituents through said peripheral outlet, external vanes on said rotor for preventing back flow of the heavier constituent toward said passageway and for preventing leakage of the lighter constituent from said passageway toward said discharge outlet, and baflle means radiating from the central portion of said rotor to deflect into the path of said internally disposed vanes fluid tending to flow axially through the rotor.

5. A rotor for a centrifugal liquid-gas separator having an axial inlet at one end thereof, a side wall diverging from said inlet, a peripheral outlet at the divergent end of said side wall, and an axial outlet at the divergent end of said side wall aligned with said axial inlet, a plurality of blades radiating from the central portion of said rotor to said side wall, said blades having outer end portions extending from the axial inlet to the peripheral outlet together with reduced inner end portions extending only for a short distance along the central portion of the rotor.

6. A'liquid-gas separator comprising a casing having mounting flanges on both ends thereof, a shaftrotatably. supported by said casing having coupling means on both ends thereof, said casing having a pair of annular chambers receiving said shaft therethrough and separated by a partition wall, a rotor carried by said shaft having an axial inlet at one end thereof, an axial outlet at the other end thereof communicating with one of said chambers and a peripheral outlet at said other end communicating with the other of said chambers, and radial vanes on said rotor having close running clearance relationship with said partition wall to seal the other of said chambers from said axial outlet of the rotor.

'7. A liquid-gas separator comprising a rotor having an axial inlet at one end thereof, an axial outlet at the other end thereof and a peripheral outlet surrounding said axial outlet, said rotor having-a separating chamber diverging from said inlet to said peripheral outlet, blades in said separating chamber for centrifugally separating heavy and light components of material entering the inlet for centrifugaldischarge of the heavier components through the peripheral outlet and for discharge of the lighter components through the axial outlet, and externally disposed sealing means on the rotor adjacent said peripheral outlet adapted to stop flow between the axial and peripheral outlets.

3. A centrifugal liquid-gas separator comprising a casing having an axial inlet at one end, separated outlets at the other end and a rotor chamber between the axial inlet and the outlets, a rotor in said chamber having a side wall member diverging from said axial inlet aligned with the casing inlet to a peripheral outlet discharging into one of the casing outlets, means defining a passageway connecting the central portion of the diverging end of the rotor with the other casing outlet, radial blades in said rotor for whirling fluid received from the inlet to centrifugally separate the heavier and lighter constituentsthereof and discharge the lighter consti tuents through said passageway and the heavier constituents through said peripheral outlet, said blades having cut-off portions adjacent the rotor side wall providing passages permitting peripheral load-equalizing fluid flow around a localized portion of the rotor.

9. A rotor for a centrifugal liquid-gas separator having an axial inlet at one end thereof, a side wall diverging from said inlet, and a peripheral outlet at the divergent end of said side wall, a plurality of blades radiating from the central portion of said rotor to said side wall, and said blades coacting with said side wall at the inlet end portion of the rotor to provide a continuous circumferential path around the inside of the rotor for permitting peripheral load-equalizing fluid flow between the vanes.

MILES LOWELL EDWARDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 521,104 Davis June 5, 1894 612,100 Hartmann Oct. 11, 1898 699,217 McCornack May 6, 1902 721,186 Hedderich Feb. 24, 1903 821,554 Truesdell May 22, 1906 980,001. Ponten Dec. 27, 1910 1,719,522 Sharples July 2, 1929 

